Work related to the development of new and improved spectroscopic methods for the determination of trace elements in biological samples is proposed. The objectives of the program include contributions to the understanding of the basis of the spectroscopic techniques, developments in instrumentation, developments in ancillary techniques of sample handling and pretreatment, and reduction to practice by demonstration of the utility of the developed techniques for elemental determinations in complex samples and selected standard reference materials. Specific aims of the project are: (1) to develop microsampling techniques for atomic emission, absorption, and fluorescence spectroscopy, (2) to further investigate the properties of a DC arc plasma jet device for elemental analysis, and (3) to develop a system for automated optimization of selected spectroscopic experiments. BIBLIOGRAPHIC REFERENCES: W. E. Rippetoe, E. R. Johnson, and T. J. Vickers, "Characterization of the plume of a DC plasma arc for emission spectrometric analysis", Anal. Chem., 47, 436 (1975). M. R. McCullough and T. J. Vickers "Determination of copper and iron in microliter samples by flame atomic emission spectrometry with a tantalum filament vaporizer", Anal. Chem., 48, 1006 (1976).